Ulysses: Jupiter’s Turn Toward the Sun’s Poles

Transcript

Ulysses set out to study the Sun from a direction no ordinary planet-bound path could provide. Planets orbit in a broad, nearly flat sheet around the Sun. That sheet is called the ecliptic. On February 8, 1992, Ulysses passed Jupiter, using the giant planet’s gravity to bend its route below that sheet and toward the Sun’s south pole. After studying Jupiter for 17 days, it continued back toward the Sun, later rising above the ecliptic to survey the north-polar region. The spacecraft observed the south-polar region from June 26 to November 6, 1994, reaching 80.2 degrees solar latitude. Its north-polar observing period ran from June 19 to September 30, 1995, also reaching 80.2 degrees. These high-latitude views showed that solar wind moved faster at the south pole than near the equator. On a later pass, Ulysses also found the Sun’s southern magnetic pole more dynamic than the north, without a fixed, clear location. By using Jupiter’s gravity to leave the planets’ usual orbital plane, Ulysses gave scientists a rare view of the Sun from above and below. Its significance rests in that distinct vantage point and the observations it made possible.